The invention relates to controlled temperature water baths which are used in medical laboratories to place thin sections of pathological tissue on the surface of the water so as to fascillitate placing the tissue, free from wrinkles on a glass slide for subsequent staining and microscopic examination.
In medical laboratories there is a department known as Histology. This department is charged with the important responsibility of preparing stained pathological or tissue slides for microscopic examination by the pathologist to determine whether or not a patient has a malignant growth or not. In one of the processes, fixed tissue specimens from patients are embedded in paraffin blocks so as to facilitate cutting this tissue into thin sections of about 3 microns in thickness. In order to facilitate placing these sections on a glass slide for subsequent staining the tissue sections embedded in the paraffin are placed in a temperature controled water bath or vessel after they are cut. That is the cut sections are laid as flat as possible on the surface of the water in such a manner that the heated water spreads the tissue out so that no wrinkles are present. As this process is carried out, particles of paraffin and or tissue surrounded or held by paraffin accumulated in the vessel. Large fragments are removed constantly with a forceps or such means. Sometimes a paper towel is used to skim the surface in an effort to remove the finer particles as well as the larger ones. At the end of the process, when all the tissues for that day have been done, the entire vessel is emptied and rinsed clean, and fresh water is placed in the vessel. In this manner it would be ready the next morning to be used, ie the water is clean and the correct temperature has been reached. If the water is too cold the tissue will not spread properly. If it is too hot the paraffin that holds the sections will melt and it will be more difficult to pick up the tissue. It should be noted that the cleaning of the vessel during or after the process described, is rather important. Quite often a pathologist will observe a particle of tissue on the stained slide during microscopic examination that does not appear to belong on the slide. In other words one may supposed to be looking at lung tissue and discover that tissue from a bowel section has been carried over onto the slide by mistake. Sometimes this is obvious and at the least it becomes questionable or problematic expecially if the tissue appears to be malignant. In this event new slides must be cut and reexamined. This problem occurs due to the fact that it is almost impossible to maintain a constant clean water bath or vessel. Consequently the accumulation of debri makes it quite difficult to spread the tissue of an area of surface water that it thoroughly clean and free from unwanted debris. The technician constantly attempts to maintain a clean water surface by using forceps for gathering up the larger more obvious particulates and occassionaly makes use of paper towels to skim the water surface. Certain tissue such as fat tends to break up and dissolve in the water bath and this constantly is a source of problem. This occurrs on a daily basis, and adds to the problem of maintaining clean water.
The invention described herein addresses itself to the aforementioned problems.